Combat Modifiers

This section covers offensive and defensive modifiers provided by position.
Favorable and Unfavorable Conditions
Generally speaking, any situational modifier created by the attacker's position or tactics applies to the attack roll, while any situational modifier created by the defender's position, state, or tactics applies to the defender's Defense. The GM judges what bonuses and penalties apply, using Table: Defense Modifiers and Table: Attack Roll Modifiers as guides.
Table: Defense Modifiers
Circumstance
Melee
Ranged
Defender sitting or kneeling
-2
+21
Defender prone
-4
+41
Defender stunned or cowering
-22
-22
Defender climbing
-22
-22
Defender flat-footed
+02
+02
Defender running
+02
+22
Defender grappling (attacker not)
+02
+03
Defender pinned
-44
+04
Defender helpless (such as paralyzed, sleeping, or bound)
+02
+02
Defender has cover
--- See Cover ---
Defender concealed or invisible
- See Concealment -
1 Does not apply if target is adjacent to attacker. This circumstance may instead improve bonus to Defense granted by cover. See Cover, below.
2 The defender loses any Dexterity bonus to Defense.
3 Roll randomly to see which grappling combatant the character strikes. That defender loses any Dexterity bonus to Defense.
4 Treat the defender's Dexterity as 0 (-5 modifier).
Table: Attack Roll Modifiers
Circumstance
Melee
Ranged
Attacker flanking defender1
+2
-
Attacker on higher ground
+1
+0
Attacker prone
-4
-2
Attacker invisible
+23
+23
1 A character flanks a defender when he or she has an ally on the opposite side of the defender threatening the defender.
2 Some ranged weapons can't be used while the attacker is prone.
3 The defender loses any Dexterity bonus to Defense.
Cover
Cover provides a bonus to Defense. The more cover a character has, the bigger the bonus. In a melee, if a character has cover against an opponent, that opponent probably has cover against the character, too. With ranged weapons, however, it's easy to have better cover than the opponent.
The GM may impose other penalties or restrictions on attacks depending on the details of the cover.
Degree of Cover
Cover is assessed in subjective measurements of how much protection it offers. The GM determines the value of cover. This measure is not a strict mathematical calculation, because a character gains more value from covering the parts of his or her body that are more likely to be struck. If the bottom half of a character's body is covered, that only gives one-quarter cover, because most vital areas are still fully exposed. If one side or the other of a character's body is covered, the character gets one-half cover.
Cover Defense Bonus
Table: Cover gives the Defense bonuses for different degrees of cover. Add the relevant number to the character's Defense. This cover bonus overlaps (does not stack) with certain other bonuses.
Cover Reflex Save Bonus
Table: Cover gives the Reflex save bonuses for different degrees of cover. Add this bonus to Reflex saves against attacks that affect an area. This bonus only applies to attacks that originate or burst out from a point on the other side of the cover.
Striking the Cover Instead of a Missed Target
If it ever becomes important to know whether the cover was actually struck by an incoming attack that misses the intended target, the GM should determine if the attack roll would have hit the protected target without the cover. If the attack roll falls within a range low enough to miss the target with cover but high enough to strike the target if there had been no cover, the object used for cover was struck. This can be particularly important to know in cases when a character uses another character as cover. In such a case, if the cover is struck and the attack roll exceeds the Defense of the covering character, the covering character takes the damage intended for the target.
If the covering character has a Dex-terity bonus to Defense or a dodge bonus, and this bonus keeps the covering character from being hit, then the original target is hit in-stead. The covering character has dodged out of the way and didn't provide cover after all. A covering character can choose not to apply his or her Dexterity bonus to Defense and/or his or her dodge bonus, if the character so desires.
Table: Cover
Degree of Cover (Example)
Cover Bonus to Defense
Reflex Saves
One-quarter (standing behind a 3-ft. high wall)
+2
+1
One-half (fighting from around a corner or a tree; standing at an open window; behind a creature of same size)
+4
+2
Three-quarters (peering around a corner or a big tree)
+7
+3
Nine-tenths (standing at an arrow slit; behind a door that's slightly ajar)
+10
+4 1
Total (on the other side of a solid wall)
-
-
1 Half damage if save is failed; no damage if successful.
Concealment
Concealment includes all circumstances in which nothing physically blocks a blow or shot, but something interferes with an attacker's accuracy.
Degree of Concealment
Concealment is subjectively measured as to how well concealed the defender is. Examples of what might qualify as concealment of various degrees are given in Table: Concealment. Concealment always depends on the point of view of the attacker.
Concealment Miss Chance
Concealment gives the subject of a successful attack a chance that the attacker missed because of the concealment. If the attacker hits, the defender must make a miss chance percentile roll to avoid being struck. (Actually, it doesn't matter who makes the roll or whether it's rolled before or after the attack roll. When multiple concealment conditions apply to a defender, use the one that would produce the highest miss chance. Do not add the miss chances together.
Table: Concealment
Concealment (Example)
Miss Chance
One-quarter (light fog; light foliage)
10%
One-half (shadows; dense fog at 5 ft.)
20%
Three-quarters (dense foliage)
30%
Nine-tenths (near total darkness)
40%
Total (attacker blind; total darkness; smoke grenade; dense fog at 10 ft.)
50% and must guess target's location